Archive for June, 2009

Inspired by all the amazing stone work I saw on a visit to Palma de Mallorca, the capital of the Balearic Island Mallorca (Spain), I started paying attention to how the voussoirs of these vaults were cut. I did need inspiration to solve the problematic issue in the previous version of the vault, its cutting pattern.

Looking up at all the stunning stone vaults taught me a lot about Stereotomy (= The science or art of cutting solids into certain figures or sections, as arches, and the like; especially, the art of stonecutting – http://www.thefreedictionary.com/Stereotomy). In the previous try, L-shaped pieces were avoided since it was thought that those would appear awkward. In fact, it can be seen on the previous image that these L-shape pieces allow to nicely turn the corner over a groin and visually (and structurally) tie the entire vault together.

This image shows how to nicely morph from a groin vault into an elliptical vault. The stereotomy language/logic shown in this curving, vaulted arcade gives an important clue how we could transition between the different recognizable parts of our vault.

As can be seen in the picture of the previous post, the cradle formwork did not entirely solve the challenge of assembling the complex pieces into the vault. Issues seemed to be the tolerances of the coated pieces and the registration of how the pieces fit together.

Luckily, a little (referring to the size of the model) stone mason volunteered to make it happen: Lara Davis. After many hours of shaving off the faces and carefully checking the digital model, the vault was assembled upside-down in its cradle. Unfortunately, because of a lack of proper interlocking of the pieces, the vault could not be assembled without gluing the pieces together.

After a long time of inactivity – slightly distracted with writing my PhD dissertation and such – , the 70-piece 3D puzzle was still waiting to be solved.

The main reason for making a scale model is to have an extra check on the stability of the vault and check effects which are not taken into consideration into the TNA: sliding failure under all loading cases for the chosen cutting pattern, possible collapse mechanisms due to support displacements, or sensibility of the vault under asymmetric live loads.

The challenge of the formwork is that it needs to be taken off after the vault has been assembled. Thanks to Katelyn for trying to make it work. At the end, it was chosen to make a cradle formwork to assemble the vault upside down. The idea was to then flip over the vault, pressing it against the supports on the base. The thrust and interlocking of the blocks should make this possible.